Elizabeth George has written another good one here.  I read A Woman After God's Heart several years ago and was challenged by it.  Then I read another of hers...can't remember the name at the moment...it was only a mediocre book.  This one on prayer is basic (because it is for "young women"?) but certainly helpful.

It has been a great place to start for preparing the Bible studies I have to lead this fall.  The girls' Bible study will springboard from Elizabeth George's book, although I will add some of my own material.  The ladies' Bible study will go from Elizabeth George's book, as well as, Praying Jesus' Way.  (I just read this paragraph again.  I am concerned my words make it sound like these books eclipse the Bible in our Bible study.  At least one lady in our group totally dislikes using any book besides the Bible.  I find the extra books help put the Biblical concepts in a teachable order for me.  Beyond that they are good resources for extra illustrations, quotes and discussion questions.)

Anyway, as with most any classes we teach the preparation for these Bible studies has impacted my prayer life for the (very much) better.  I think my favorite point from George's book is the following:  Learning to pray is not one of those things we can put on our to-do list and then, at the end of a prescribed amount of time, scratch that baby off the list.  Elizabeth George contemplated her own prayer life on the tenth anniversary of her salvation.  Twenty years later she admits, “And I want to tell to you right now—I am still learning how to pray!” 

Looking for a good book to read with your daughter?  I think this would be a great place to start looking.